An image forming apparatus such as color printer employs an LED exposure method. For example, a color printer employing the LED exposure method, includes four drum units, which are provided corresponding to colors of yellow, magenta, cyan, and black and are disposed in parallel in an apparatus body, and an LED head, which is provided corresponding to each of the drum units and includes a plurality of LEDs arrayed linearly.
A stacker cover is provided on an upper surface of the apparatus body. The stacker cover is supported on a rotary shaft extending along the upper edge of the apparatus body and rotates about the rotary shaft so that the upper surface of the apparatus body can be opened and closed. The four LED heads are attached to the stacker cover. When the stacker cover is closed, each LED head opposes a photoconductor, which is provided in the corresponding drum unit, from above. In addition, when the stacker cover is opened, the LED heads are disposed outside the apparatus body. In this state, each drum unit can be exchanged (for example, refer to JP-A-2003-112446).